Method of molding shoe soles



P. A. SPERRY METHOD OF MOLDING SHOE SOLES Sept. 15,. 1942.

Filed Jan. 27, 1940 INVENTQR. paazz/fl J m/73y Patented Sept. 15, 1942 METHOD OF MOLDING SHOE SOLES Paul A. Sperry, New Haven, Conn, assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application January 27, 1940, Serial No. 315,992

4 Claims.

This invention relates to a shoe sole, particularly of the type which has an outer bottom surface capable of resisting slipping, such as more fully described in my co-pending application,

Serial No. 177,237, filed November 30, 1937, and which has matured into Patent No. 2,206,860, and i this invention has for one of its objects to mold a shoe sole in such form that cutting of the sole in the manner described in my co-pending application, Serial No. 158,711, filed August 12, 1937, willbe unnecessary.

Another object of the invention is to provide for molding a sole so that it will be comparable to the form provided by cutting and yet may be provided with greater facility and economy.

With these and other subjects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is a bottom plan view of a finished shoe sole;

Fig.3 is a bottom plan view of the sole at one step in the operation of the molding;

Fig. 3 is a sectional view on substantially line 33 of Fig. 1 with powder applied;

provide a shoe sole which will have the antislipping properties of this article in my last above-mentioned application and which may be formed in a different way, such as by molding, I have molded a sole with grooves extending laterally and of such distance apart as to provide sections of the desired dimension, the molding being done by pressure, leaving the rubber material in a semi-plastic, doughy condition, so that 0 when opposed forces are applied to the material in a lengthwise direction of the sole, the sections will be brought closer together so as to cause the side walls of the grooves to substantially contact, and I provide a means for preventing these walls from sticking together in a known manner.

the following is a more detailed description of the present embodiment of this invention, illustrating the preferred means by which these advantageous results may be accomplished:

With reference to the drawing, Ill designates a shoe sole which by molding is of a length greater Fig. 4 is a fragment of the mold for the form shown in Fig. 3;

Fig. 5 is an enlarged view with the material forced so as to close the grooves formed as shown in Fig. 3, except for the powder or like material;

Fig. 6 illustrates the material of Fig. 5, as located in a mold;

Fig. 7 is a bottom plan of a fragment in the form shown in Fig. 5;

Fig. 8 is a greatly enlarged section similar to Fig. 3;

Fig. 9 is a greatly enlarged section similar to Fig. 5;

Fig. 10 is a modification of a different shape of groove, extending laterally across the shoe sole, before pressure is applied to close the groove;

Fig.11 is a bottom plan view after the grooves of Fig. 10 have been closed by pressure to move the opposite sidewalls together.

In the formation of rubber shoe soles, with sections in contact with each other extending across the shoe sole, the sections are formed by cutting into the shoe sole and stopping short of passing through the shoe sole, such as illustrated in my co-pending application, Ser. No. 177,237, above mentioned. The sole is fed forwardly as the cutting is performed. The operation is a than the length desired for the sole in its finished form. Suitable fins I! in the mold l8 provide grooves ll extending laterally across the sole. These grooves have substantial width and provide side walls 12 and I3, substantially spaced from one another. The molding is of rubber of a very flexible material, such as described in my abovementioned article application, and the molding is carried on to an extent of curing of the rubber such that the same is relatively plastic and doughy when taken from the molding. It is possible that this portion of the operation may be performed by calendering.

At this point in the process some sort of treatment is given to walls I! and I3 of each groove, 0 such, for instance, as placing powder l5 upon these walls, or some Holland cloth or thin material may be inserted which may later be removed, to prevent these walls from contacting and sticking.

The length of the sole is then foreshortened by suitable pressure, such, for instance, as in a mold I4, where the shape of the article may be controlled and the walls 12 and I3 are brought into substantial contact, except for a very thin film of powder as shown in Figs. 5, 6, 7, and 9, so that their surfaces abut or abut except for such separating material as may be placed within the very delicate one and requires careful handling groove which is of a relatively small dimension and accurate machine work, and, in order to and is inconsequential. After this foreshortening has been accomplished, the sole is vulcanized, which firmly sets the sole in this shape and maintains the sole with lateral extending slits and flexible sections, such as is required for the.

the method and construction i1lustrated,"but I desire it to be understood that I reserve the privilege of resorting to all the equivalent changes to which the construction and method are susceptible, the invention being defined and limited only by the terms of the appended claims.

I claim:

. .1. The method of making a slip-retarding shoe sole which comprises shaping a thermoplastic material with lateral grooves in its outer surface, partly curing said sole, protecting the spaced opposed surfaces of the grooves against sticking together, and then permanently reducing the lengthwise dimension of the material united at 30 the base of the grooves by applying opposed forces to the material in the'lengthwise direction of the sole so as to cause the wall surfaces of the grooves to approach each other.

2. The method of making a slip-retarding shoe sole which comprises molding and shaping thermoplastic material with lateral grooves in its outer surface when taken from the mold, partly curing said sole, protecting the spaced opposed surfaces of the grooves against sticking together, then compressing the material in-a direction at right angles to the grooves to cause the wall surfaces of the grooves to approach each other and contact, and then finishing the curing of the sole.

3. The method of making a slip-retarding shoe sole which comprises shaping a thermoplastic material with lateralgrooves in its outer surface extending in a serrated path, partly curing said sole, protecting the spaced opposed surfaces of the grooves against sticking together, and then forcing the material from opposite directions toward each other to cause the wall surfaces of the grooves to approach each other.

4; The method of making a slip-retarding shoe sole which comprises shaping a thermoplastic material with lateral grooves inits outersuriace extending in a serrated path, partly curing said sole, protecting the spaced opposed surfacesfof the grooves against sticking togethergperrna nently reducing the lengthwise dimension of the material united at the base of the grooves by applying opposed forces to'the material in the lengthwise direction of the sole so as to cause the wall surfaces of the grooves toapproach each other, and then finishing the curing of the sole.

PAUL A. SPERRY. 

